Huang et al. [38] reported that the level of PiRNA-31,106 is high in BC tissues and cell lines (MDA-MB-231 and MCF-7), which promotes the m6A methylation levels and facilitates METTL3 expression that further promotes BC progression by upregulating the expressions of MDM2, CDK4, and cyclinD1 [38]. This evidence concerns the gene CDK4 and breast cancer.